Apparatus for coating continuously produced filaments



Feb. 17, 1959 R. H. BRAUTIGAM APPARATUS FOR COATING CONTINUOUSLY PRODUCED FILAMENTS 2 Sheets-Sheet 1 Filed June 15, I 1955 R m m m RICHARD H. BRAUTKSAM BY; a

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. ,v a! ia e AT TORN EYS Feb. 17, 1959 R. H. B'RAUTIGAM APPARATUS FOR COATING CONTINUOUSLY PRODUCED FILAMENTS 2 Sheets-Sheet 2 Filed June 15, 1955 INVENTOR. RICHARD H. BRAUTIGAM ATTORNEYS United States Patent APPARATUS FOR COATING (Z'ONTIFIIHJUSLY PRODUCED 'FILAMENTS Richard H. Brautigam, Anderson, S. C., :nssignor -to Owens-Corning Fiberglas Corporation, a corporation of Delaware Application June 15, '1955, Serial No. 515,651

Claims. (CL 118-234) This invention relates to an apparatus for applying a liquid coating to longitudinally moving, continuousjfilamentary materials and, more particularly to improvements in those portions of the apparatus which pick up and transfer the liquid coating material'from a'supply to the filamentary material itself.

In describing the instant invention it-will be-"disclosed and illustrated in connection with the application of a coating material to a group of continuous glass filaments or fibers which are simultaneously produced and "then laterally grouped together to form a continuous-glas's fiber strand. Continuous glass fiber strands in many commercial installations are produced by maintaining asupply of molten 'glass inaglass melteror bushin'g" which has a plurality of minute orifices distributed over its bottom. A fine "stream of glass flows through each or the orifices and the cooling streams "are longitudinallydrawn '-at high speed'to'attenuate them into' glass fibers. Coin- 'mercial bushings usually have upwards of 200 orinore orifices or tips through each of which an individualfi'lament is pulled and the filaments are combined by lateral association to form a single strand. The 200 -'or-rnoi'e orifices or tips are spaced over'a considerable-area and the filaments, therefore,-extend in theshape of a fan leading from the spaced orifices to a guide or gathering shoe.

In order to insure the application of a'size, lubric'a'nt or other coating to each of the filaments,'applicators of many diiferent'types have been devised which transfer the liquid coating material to the filaments before they are associated into 'a'str'and'or 'at theitimeof their:asso- 'ciation together to' form a strand. In'order to insure'that each of the 200 or more filaments in the strand is individually coated it is preferable'to apply the' liquid "coating to the filaments before they are associated together in'strand form.

The instant invention has as its primary object-the provision of means or apparatus for applying the liquid coating to each of the individual filaments prior'to' their association in a strand. 'It is a further object of thisinvention to providean apparatus'for applying a liquid coating'to a group-of continuous filaments'so designed as to provide acons'tan't, uniform supply of the coating material and 'to'apply it to each of the filaments with a minimum of interference withor increase in the resistance to the longitudinal movement of the filaments as they are being attenuated.

'It is *astill further'ohject of the *inverition'to'provide anapparatus for the application of a liquid co'atih'g medium to a fan of continuous glass filaments 'at"a' location close to the point of'association of the filaments'intva strand, thereby simplying the operation,'reducing th'er'esistance to movement'of thefilam'entscaused by their:- plicator apparatus, obviating many of the difiiculties' causing wastage of the coating material, andeh'ziblin'guhiform'and'accurate coating to be accomplished.

The foregoing objects of the invention and other (1b- Z,8?3,7l8 Patented Feb. 17, 1959 2 i'ects-and'advantages of-apparatus embodying the inventionzwill-be betterz'understood from the. specification be- .low andfromihe drawings-in which:

Fig. 1 .is :a fragmentary, somewhat diagrammatic view in elevation 'of apparatus embodying the invention :as combined'with filament i-fortning and strand winding apparatus known in the art.

:Fig. 2 is an end -view"in elevation takenfrom the right sideinliig. 1 and showing only the strand'coating apparatus embodying .the invention.

Fig. 3 is a plan view of apparatus embodying the invention.

Fig. 4 is'a' fragmentary view-'in-eleva'tion on a greatly enlarged :scale of --a portion of apparatus embodying the invention, specifically illustrating the application of the liquid coating to the filaments and their association to- 'geth'er'to form a strand.

Fig. 5 is a fragmentary somewhat diagrammatic vertical "sectional view taken 'generally'along the'line 5-5 of Fig. 3 and, like Fig.4, illustrating the application of coating material'to the filaments.

A-multifilament, continuous glass fiber 'strand'may be forme'd'from a plurality of individual fibers 10 attenuated from "fine streams of glass which flow through a corre- Spon'dinghumber 'of orifices in the bottom of 'a glass 'melter'or bushing generally in'dicatedatll. It will be observed inFigs. l and '2 that the fibers or filaments 10 extend in a plurality of lateral rows because (Sf-the neces si ty for'laterally'spacing the individual orifices-from which they are pulled. ln'Fig. l the filaments 10 are illustrated as-'extendingtransversely across the bushing -ll'w'vith', sa "-50 or more in each individual row and in Fig. Z' i't 'can'be'se'en that the bushing 11 has four or more rows of filament orifices.

"In-order to-associate 'the plurality of individual filaments 10 to form 'a multifilamentstrand ltthey'are led through an arcuate guide -generally'indicate'd"at-13 and 'shown in the drawings-as having '-a recessed 'V-sh'aped 'groove 14 (Fig. 3)-in its arcuate edge.

After 'a'ssociation-ofthe 200'or'1nore"filaments 10 to form the strand 12 it may'be'led downwardly through a traverse 15 and ontotheexterio'r'of'a 'rotary'spool generally indicated at "16 -for winding the continuous tus for driving the transfer 'belt '23 including a motor 24 and gear box and transmission 25.

"Thetransfer belt 23-is mounted upon acrowned drum '26 which is, in turn, supported'by a sha'ft'27 driven fromthe gearing 25 and extending horizontally over the liquid material'supply tank 22'at such a level that the peripheral surface of the drum 26 'dips'beneath the'level of asupply of coating material'generally indicated at 28 in the tank "22. The level of the coating material 28 is maintained by a weir 29 'extending'transversely across the'tank '22 and separating the tankj22 into a supply compartment 30 and an overflow "compartment 131. .A coating 'rna'teri'al input line 32 leads to'the bottom of the 'supply'cornpartment 30 .anda return line 33 leadsfrom "the overflow compartment 31 to a pump and supply for "thejcoating material 28, not shown in the drawings.

The belt 23 is also engaged over a guide .bar 34 mounted "in a'fra'me '35 and extending parallel to the "axis of the drum 26 above andin 'front of thesupply tank 22. As can best be observed in FigsfB and 5,

3 when the belt 23 is in position on the drum 26 and guide bar 34, its front edge 'is vertically positioned directly above the apex of the V-slot 14 in the arcuate guide 13. The guide 13 is adjustably positioned in the bracket 21 by means of a thumb nut 36 in order that the apex of the slot 14 may be laterally positioned relative to the width of the belt 23 so that the fan of filaments 10 at the point of engagement with the belt 23 will lie at one side of the center of the belt 23 as can best be seen in Figs. 1 and 4.

In operation, the drum 26 is rotated at a constant speed so that the belt 23 is moved through the pool of coating material 28 and picks up a layer of the coating substance on its outer surface. The layer of coating material generally indicated at 37 (Fig. maybe leveled by a doctor blade 38, if desired, and is carried forward across the span of the belt 23 and around the guide bar 34 moving in the same direction around the guide bar 34 as the filaments 10. The filaments wipe through the layer of coating material 37 at the point generally indicated by the reference number 39 in Figs.

and 5 with a controlled quantity of the material adhering to each of the filaments 10 as that filament is submerged in and pulled out of the coating 37. The quantity of material adhering to each of the filaments 10 is referred to as controlled because by proper coordination and relationship of the viscosity, tempera-- 23 and the nose or guide bar 34 to prevent the ingress of contaminants and the cover 40 has a visor 41 which can be swung downwardly and forwardly to the position shown in dotted lines in Fig. 2 to cover the guide bar 34 and the forward .portion of the belt 23 when the apparatus is down 1in. oi:de r ,to preventslugs or beads of glass from striking the belt 23.

Apparatus embodying the instant invention has many advantages over previously designed applicators and even over such applicators as may have been employed which utilize a roller for transferring the coating material 'from a supply to the filamentary material to be coated. Among these many advantages the following are included.

.It is desirable that all of the filaments contact the coating substance for as brief an extent as possible because the passing of each filament into, through and out of the coating substance creates resistance to the movement of the filament and the longer the extent of submersion in the coating material the greater the resistance. Preferably, of course, all of the filaments should engage the transfer device, in this case the belt 23, as near to tangentially as possible. However, because the high num ber of filaments that are combined to form the strand must be pulled from a "corresponding number of tips or filament orifices which must be spread over a substantial lateral area, the filaments approach the surface of. the coating device from a number of different positions and some of the filaments will enter the film 37 of coating material before others of the filaments and will remain in the film for a greater extent. By moving the film 37 of coating material onthe belt 23 around an arc of small diameter the extent of immersion of the filaments in the fllm 37 is far less than it would be, for example, if the filaments were engaged in a film of'coating material 37 moving 'on the surface of a roll having a diameter like thatof the drum 26 By the use of a coating transfer belt 23 according to the invention a large area'of pick up around the drum 26 may be submerged in the liquid and a 'small area oftransfr to the filaments around the guide a bar 34 may also be employed.

By the utilization of a small diameter are of contact between the filaments and the coating transfer belt 23, it may be positioned more closely adjacent the guide 13 than would be possible using a large diameter drum or guide bar 34. It is thus possible to engage the fan of filaments 10 at a point where the fan is narrow and the filaments in the fan are closelyadjacent each other. This results in all of the filaments entering the film 37 of coating material as a group so that the only shearing within the coating material itself takes place at the sides of the group of filaments 10'rather than around each filament 10. This area of engagement can be kept so small that it need utilize only approximately one-half of the width of the transfer belt 23 and thus when the surface of the transfer belt 23 becomes worn from the abrasive effect of the filaments 10 on the belt 23, it may be slipped off the drum 26 and guide bar 34 and turned over to present a new surface.

By moving the point of contact of the filaments 10 with the coating layer 37 in close to the guide 13, spraying of the coating material off the fan of filaments 10 is reduced since it remains on the filaments for only a short time before the filaments are associated together by the guide 13. In addition the deleterious results of pad breakage are reduced. If the filaments forming the strand 12 snap at their engagement with the belt 23, as sometimes occurs, since they are engaged over only a short distance laterally, all of the filaments will break at approximately the same length and, therefore, the strand 12 will be broken more nearly directly across its width than. is the case where the filaments 10 are en- .gaged in a wider part of the fan with a transfer roller or othermeans extending laterally over agreater distance. .A pad .break under these conditions with the progressive breaking of filaments across the engagement results in the strand 10 having a beveled end, i. e., some of the filaments may extend for many yards beyond others of the'filaments in the strand, making it virtually impossible to pick up the end of the strand off the spool-16.

Utilization of a belt 23 according to the invention also permits a stationary nose or guide bar 34 to be employed, as contrasted to a roller. This is advantageous since it eliminates the necessity for bearings and maintenance and it obviates the close tolerances required in mounting a rotary member to engage the filaments without eccentricity or wobbling. If desired, of course, the guide bar 34, though stationary, may be mounted upon an'eccentrie positioning device so that its precise location relative to the filaments 10 can beadjusted to apply proper tension on the belt 23 and to engage the fan of filaments 10 at the most advantageous point and angle.

With respect to stationary pad applicators, for example that type where the coating material is dripped onto a pad of felt or similar material and the coating material is wiped oif the pad by the filaments sliding over its surface, the instant application has additional advantages. In the use of a pad type applicator it is necessary to drip an excessive quantity of coating substance onto the pad in order to insure that a sulficient quantity is present to coat the filaments.- This excessive quantity of material drips from the pad and is frequently carried off the pad by the filaments, squeezed off the filaments when they areguided together and then drips off the guide. This excess coating liquid drips downwardly onto the floor or machinery in the winding room and creates conditions adverse to efiicient operation. By the concording to the invention this necessity for excessive mafterial and consequent dripping iseliminated. Furthera l 7 transferred to the filaments 10 is more, all material delivered by the belt 23 which is not returned by the belt 23 to the pool in the tank 22.

When lowvis cosity liquids such as sizes are applied by prior art 'pad or roll applicators the difiiculties discussed generally above'are even harder to overcome than when high viscosity coating materials are applied by such prior art devices. However, because of the large area of immersion in and small area of transfer of the liquid, the belt applicator of the invention is particularly effective in use for applying thin coating materials such as size used for treating filaments to be employed in textiles.

I claim:

1. Apparatus for applying a liquid coating to longitudinally moving, continuous, filamentary material, said apparatus comprising, in combination, a liquid supply tank having an open top, a driven roller journalled on a horizontal axis and positioned with at least a substantial portion of its periphery within said tank and beneath the surface of the supply of liquid therein, means for rotating said roller, a belt guide positioned laterally of said roller, said belt guide having a cylindrically curved outer surface of diameter substantially smaller than the diameter of said roller, a continuous belt extending around said roller and said belt guide and driven by said roller over said belt guide and a filament guide positioned beneath said belt guide for guiding said filamentary ma terial into substantially tangential contact with the outer surface of said belt at the outer side of said belt guide.

2. Apparatus according to claim 1 in which the belt guide is a non-rotatable cylindrical member having a smooth surface and is located with its outer surface only slightly beyond the edge of said tank and said filament guide is located beneath said guide and laterally beyond the edge of said tank, whereby said filamentary material moves from contact with said belt to said filament guide exteriorly of said tank.

3. Apparatus for applying a liquid coating to longitudinally moving, continuous, filamentary material, said apparatus comprising, in combination, a generally horizontal liquid supply tank having an open top, a driven roller journalled on a horizontal axis and positioned with l at least a substantial portion of its periphery Within said tank and beneath'the level of the surface of the supply of liquid therein, means for rotating said roller, a belt guide positioned laterally of said roller at the side of said tank, said belt guide having a cylindrically curved outer surface of diameter substantially smaller than the diameter of said roller, a continuous belt extending around said roller and said belt guide and driven by said roller over said belt guide, a filament guide positioned outside said tank and beneath the outer side of said belt guide for guiding said filamentary material into contact with the outer surface of said belt at the outer side of said belt guide and means for circulating liquid coating into and out of said tank.

4. Apparatus for applying a liquid coating to longitudinally moving, continuous, filaments, said apparatus comprising, in combination, a liquid supply tank having an open top, at least two cylindrical elements mounted on spaced, parallel, horizontal axes, an applicator belt extending around said elements, one of said elements being located above said tank at such a level relative to its diameter that at least a portion of said belt extends beneath the surface of the liquid supply in said tank,

another of said elements being located laterally of the 'fir'stmentioned element at such distance therefrom that at least a portion of said belt passing around said other element extends horizontally beyond the edge of said tank, the diameter of the second-mentioned one of said elements being small whereby movement of said filaments through a film of liquid on said belt enroute to and from substantially tangential contact with said belt is of short duration, at least one of said elements being rotated under power for driving said belt around said elements in a direction moving up over the first mentioned element, generally horizontally to and down around the second mentioned element, and means for guiding said filamentary material into substantially tangential contact with the outer side of said belt at the outer side of the second mentioned element.

5., Apparatus according to claim 4 in which the diameter of the second mentioned one of said elements is substantially smaller than the first mentioned one of said elements.

References Cited in the file of this patent UNITED STATES PATENTS 

